package com.cloudgarden.resource;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Vector;

import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Cursor;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Widget;

/**
 * Class to manage SWT resources (Font, Color, Image and Cursor)
 * There are no restrictions on the use of this code.
 *
 * You may change this code and your changes will not be overwritten,
 * but if you change the version number below then this class will be
 * completely overwritten by Jigloo.
 * #SWTResourceManager:version4.0.0#
 */
public class SWTResourceManager {

    private static HashMap resources = new HashMap();
    private static Vector users = new Vector();
    private static SWTResourceManager instance = new SWTResourceManager();

    private static DisposeListener disposeListener = new DisposeListener() {
        public void widgetDisposed(DisposeEvent e) {
            users.remove(e.getSource());
            if (users.size() == 0)
                dispose();
        }
    };

    /**
     * This method should be called by *all* Widgets which use resources
     * provided by this SWTResourceManager. When widgets are disposed,
     * they are removed from the "users" Vector, and when no more
     * registered Widgets are left, all resources are disposed.
     * <P>
     * If this method is not called for all Widgets then it should not be called
     * at all, and the "dispose" method should be explicitly called after all
     * resources are no longer being used.
     */
    public static void registerResourceUser(Widget widget) {
        if (users.contains(widget))
            return;
        users.add(widget);
        widget.addDisposeListener(disposeListener);
    }

    public static void dispose() {
        Iterator it = resources.keySet().iterator();
        while (it.hasNext()) {
            Object resource = resources.get(it.next());
            if (resource instanceof Font)
                 ((Font) resource).dispose();
            else if (resource instanceof Color)
                 ((Color) resource).dispose();
            else if (resource instanceof Image)
                 ((Image) resource).dispose();
            else if (resource instanceof Cursor)
                 ((Cursor) resource).dispose();
        }
        resources.clear();
    }

    public static Font getFont(String name, int size, int style) {
        return getFont(name, size, style, false, false);
    }

    public static Font getFont(String name, int size, int style, boolean strikeout, boolean underline) {
        String fontName = name + "|" + size + "|" + style + "|" + strikeout + "|" + underline;
        if (resources.containsKey(fontName))
            return (Font) resources.get(fontName);
        FontData fd = new FontData(name, size, style);
        if (strikeout || underline) {
            try {
                Class lfCls = Class.forName("org.eclipse.swt.internal.win32.LOGFONT");
                Object lf = FontData.class.getField("data").get(fd);
                if (lf != null && lfCls != null) {
                    if (strikeout)
                        lfCls.getField("lfStrikeOut").set(lf, new Byte((byte) 1));
                    if (underline)
                        lfCls.getField("lfUnderline").set(lf, new Byte((byte) 1));
                }
            } catch (Throwable e) {
                System.err.println(
                    "Unable to set underline or strikeout" + " (probably on a non-Windows platform). " + e);
            }
        }
        Font font = new Font(Display.getDefault(), fd);
        resources.put(fontName, font);
        return font;
    }

    public static Image getImage(String url, Control widget) {
        Image img = getImage(url);
        if(img != null && widget != null)
            img.setBackground(widget.getBackground());
        return img;
    }

    public static Image getImage(String url) {
        try {
            url = url.replace('\\', '/');
            if (url.startsWith("/"))
                url = url.substring(1);
            if (resources.containsKey(url))
                return (Image) resources.get(url);
            Image img = new Image(Display.getDefault(), instance.getClass().getClassLoader().getResourceAsStream(url));
            if (img != null)
                resources.put(url, img);
            return img;
        } catch (Exception e) {
            System.err.println("SWTResourceManager.getImage: Error getting image "+url+", "+e);
            return null;
        }
    }

    public static Color getColor(int red, int green, int blue) {
        String name = "COLOR:" + red + "," + green + "," + blue;
        if (resources.containsKey(name))
            return (Color) resources.get(name);
        Color color = new Color(Display.getDefault(), red, green, blue);
        resources.put(name, color);
        return color;
    }

    public static Cursor getCursor(int type) {
        String name = "CURSOR:" + type;
        if (resources.containsKey(name))
            return (Cursor) resources.get(name);
        Cursor cursor = new Cursor(Display.getDefault(), type);
        resources.put(name, cursor);
        return cursor;
    }

}
